Conventional fiber reinforced polymers (FRPs) require polymers such as epoxies that are not biodegradable, which have a significant impact on the environment. The first phase of the thesis aims at replacing conventional polymers with sustainable bio-polymers. The tensile mechanical properties of glass-FRP (GFRP) laminates using two types of organic furfuryl alcohol bio-resins extracted from renewable resources, such as corncobs, were investigated. Results are compared to control specimens fabricated using conventional epoxy resin. It was shown that by careful selection of viscosity of bio-resin, and type and dosage of catalyst, similar mechanical properties to epoxy-GFRP can be achieved. The second and third phases consisted of durability testing of the bio-resin GFRP. A total of 160 tension coupons and 81 unconfined and confined concrete cylinders wrapped with bio-resin-GFRP were studied. Conditioning was achieved by immersion of the specimens in saline solutions with 3% salt concentration, at 23, 40 and 55 degrees Celcius, for up to 300 days. Specimens were compared to epoxy-GFRP specimens aged in the same environment. Deterioration was quantified by tensile testing of the coupons and compression testing of the cylinders at various stages of exposure. The bio-resin-GFRP showed 33% less tensile strength retention than the epoxy-GFRP. The epoxy-GFRP and bio-resin-GFRP wrapped cylinders had the same un-aged confined axial compressive strength (fcc’), essentially a strengthening ratio (fcc’/fc’) of 2.24. After 300 days, the (fcc’/fc’) ratio retentions for the bio-resin-GFRP was 73% at all temperatures. Using the Arrhenius model, it was predicted that 61% retention in tensile strength of the bio-resin-GFRP and 65% retention of the compressive strength of wrapped cylinders would occur after 100 years in an environment with a mean annual temperatures of 10 degrees Celcius. / Thesis (Master, Civil Engineering) -- Queen's University, 2013-08-24 00:02:25.683

The emergence of closed-loop Brayton cycle power plants, such as the PBMR, resulted in the need to simulate start-up transients for industrial multi-stage axial flow compressors operating at subsonic conditions. This implies that the delivery pressure and power requirements must be predicted for different mass flow rates and rotational speeds while operating in the first and fourth quadrants on the compressor performance charts. Therefore, an analytical performance prediction model for subsonic multi-stage axial flow compressors had to be developed that can be integrated into a generic network analysis software code such as Flownex. For this purpose, performance calculations based on one-dimensional mean-line analysis demonstrated good accuracy, provided that the correct models for losses, incidence and deviation are used. Such a model is therefore the focus of this study. A preliminary analytical performance prediction code, with the capability of interchanging between different deviation and loss models is presented. Reasonably complex loss models are integrated in association with the correct incidence and deviation models in a software package called "Engineering Equation Solver" (EES). The total pressure loss calculations are based on a superposition of theoretically separable loss components that include the following: blade profile losses, secondary losses and annulus losses. The fundamental conservation equations for mass, momentum and energy for compressible "rotating pipe" flow were implemented into the performance prediction code. Performance prediction models were validated against experimental data and evaluated according to their ease of implementation. Verification was done by comparing simulation results with experimental work done by Von Backstrom. This includes a calculation to determine the uncertainty in the experimental results. Furthermore, since the conventional definition of isentropic efficiency breaks down at the boundaries of quadrants on the performance charts, a new non-dimensional power formulation is presented that allows for the calculation of the compressor power in all of the relevant quadrants. Good comparison was found between simulation results and measurements in the first and fourth quadrant of operation. / Thesis (M.Ing. (Nuclear Engineering))--North-West University, Potchefstroom Campus, 2007.

Elements of an individuals occupational exposure, such as their posture can affect their comfort during work, and also their long term musculoskeletal health. Knowledge as to the extent of the influence of particular aspects of the exposures can help in providing guidance on risk evaluation, and direct future technical design focus. In many situations the exposures interact, and even if the effects of individual exposures are understood, the interactions are often less so. This is certainly the case with off-road driving exposures. Specific investigations have focussed on the effects of vibration exposure, resulting in the development of international standards and guidelines on measurement and evaluation of exposure. Consideration of the posture of the operator can be accomplished through postural assessment tools, although none of the currently available methods are developed specifically for use within a vehicle environment. The issues of both the posture of the operator and the seated vibration exposure are particularly apparent in off-road agricultural driving environments, where the driving task dictates that operator is often required to maintain specific postures whilst also exposed to whole-body vibration. In agriculture, many of the tasks require the operator to maintain axially rotated postures to complete the task effectively. The analysis of the combined effects of the axial rotation of the operator and the whole-body vibration exposure has been limited to a few studies within the literature, and is currently poorly understood. The overall aim of the thesis was to assess the influence of axial rotation and whole-body vibration on the musculoskeletal discomfort of the neck and trunk, in order that the true extent of the exposure risk may be evaluated. A field study was conducted to determine the common characteristics of some typical exposures, to provide a basis for the laboratory studies. A survey of expert opinion was conducted, examining the knowledge and experience of experts in assessing the relative influence of axial rotation and whole-body vibration on operators musculoskeletal health. The main investigations of the thesis are focussed in the laboratory, where the objective and subjective effects of axial rotation (static and dynamic) and whole-body vibration were investigated. Objective measures included the investigation of muscular fatigue in response to exposures. The tasks investigated in the field study indicated that the exposures often exceed the EU Physical Agents Exposure Limit Value, and that the axial rotation is a large component of the postures required. The survey of expert opinion concluded that combined exposure to axial rotation and whole-body vibration would increase the risks of lower back pain, and that acknowledgement of combined exposures should be included when assessing for risk. The results of the laboratory studies indicated that the greatest discomfort was present when subjects were exposed to axial rotation in the neck and shoulders. Out of the 8 muscles investigated, at most 6 of the 8 indicated fatigue during an experimental exposure. The muscle group which was affected most by the exposures was the m. trapezius pars decendens. Findings demonstrated that when subjects were exposed to axial rotation and whole-body vibration they indicated discomfort and their muscles fatigued. However, there was poor correlation between the sites of discomfort and the location of muscular fatigue. The discomfort findings suggest that there is an increased risk of discomfort from experiencing axial rotation together with whole-body vibration. Investigations of muscular fatigue do not substantiate this finding.

The purpose of this research was a proof of concept using a fan motor stator as transducer to monitor motor rotor and attached axial fan for mechanical motion. The proof was to determine whether bearing faults and fan imbalances could be detected in vane-axial fans using Motor Electrical Signature Analysis (MESA). The data was statistically analyzed to determine if the MESA systems could distinguish between baseline conditions and discrete fault frequencies for the three test conditions: bearing inner race defect, bearing outer race defect, and fan imbalance. The statistical conclusions for these proofs of concept were that MESA could identify all three faulted conditions.

Magíster en Ciencias de la Ingeniería, Mención Ingeniería Sísmica. Ingeniero Civil / El terremoto del Maule de 2010 ocurrido en Chile dejó un gran número de edificios de las construcciones modernas con daños, éstos debido a requerimientos arquitectónicos, poseen discontinuidades del tipo bandera. Un muro bandera se produce cuando hay una extensión de la longitud del muro para los pisos superiores, es decir, a partir de cierta altura el largo del muro cambia, generando una abertura en los bordes de los edificios. El nivel de discontinuidad en la base no ha sido tratado experimentalmente y por lo tanto es necesario observar su impacto estructural. En esta investigación, se estudia experimental y analíticamente el comportamiento de muros esbeltos de hormigón armado tipo bandera frente a una carga axial constante y un desplazamiento lateral cíclico, para así poder comparar los resultados obtenidos con modelos de elementos finitos o modelos predictivos utilizados en trabajos anteriores. Para lograr llevar a cabo el estudio experimental, se dispone del laboratorio de estructuras recién construido que contempla un muro y losa de reacción, al que se diseñó y construyó un sistema restricción lateral y carga axial. Se construyen cuatro probetas de hormigón armado las cuales fueron diseñadas con una altura al punto de aplicación de la carga lateral de 2.8m, un espesor de muro de 15cm y una longitud de 90cm. Todos los ensayos son realizados bajo las mismas condiciones de carga axial constante y carga lateral cíclica aplicada a nivel de techo. Para la obtención de las deformaciones principales, se han instrumentado todos los muros a ensayar con strain gages, LVDT y fotogrametría. Los resultados experimentales muestran que el impacto de la abertura es relativamente bajo, dado que todos los muros tienen capacidad y deformaciones de techo similar, sin embargo la utilización de discontinuidad acelera la degradación, demostrando que los muros banderas, en especial el de mayor discontinuidad, fallan antes que el rectangular. Los modelos en elementos finitos realizados son capaces de capturar de buena forma la respuesta, mostrando la degradación y falla obtenida en los ensayos al incorporar un modelo de acero con pandeo, además el mayor efecto de discontinuidad tipo bandera se obtiene ejecutando modelos de muros con mayor relación de aspecto (edificios altos) con aberturas pequeñas, debido a la alta concentración de daño en la discontinuidad.

Ingeniero Civil / En la práctica constructiva actual se ha hecho frecuente el uso de muros esbeltos con secciones compuestas o complejas, entre los cuales se encuentran los muros T, que constituyen el objeto de estudio de la presente memoria. Específicamente se estudia en forma analítica el efecto que tiene el confinamiento y la cuantía de borde en el comportamiento de este tipo de muros ante la aplicación de una carga pushover, para lo cual se trabaja con el programa SAFE-Toolbox, el cual corresponde a una plataforma de elementos finitos que permite estimar la respuesta de un elemento estructural ante la aplicación de una determinada carga. En primer lugar, se valida el elemento tipo shell con capas mediante la comparación con experimentos disponibles en la literatura. Luego, se recopila información sobre las características más frecuentes que se pueden encontrar en los muros de sección transversal T de los edificios chilenos (enfocándose en la Región Metropolitana), de modo de generar una base de datos lo suficientemente robusta para desarrollar un montaje experimental: definiendo dimensiones de las probetas, armadura, cuantías de borde, etc. Finalmente, se desarrollan modelos numéricos de muros T en el programa SAFE-Toolbox para estimar analíticamente los resultados que se pudieran obtener del experimento.

Title: Detection of rheological changes in the axial system of pregnant women using the TVS method. Objectives: The aim of this thesis is to evaluace the effect of pregnancy on the biomechanical properties of the spine. Methods: TVS vibration diagnostic methods were applied to six pregnant women twice during pregnancy. It was investigated ability of axial system to dampen vibration spreading through out the spine. The ability of every single segment to damp vibrations were compared with each other at the beginning and during pregnancy. Results: TVS method used for purpose of this paper has been proved adequate to provide information about the resonant frequencies and the total attenuation of the spine with sufficient accuracy, so that the biomechanice changes of axial system during pregnancy could be decidly identified. Comparison of the frequency dependency and total attenuation of spine indicated increase of total attenuation of the spine and also increase of flexibility of the spine in all investigated probands. Keywords: gravidity, pregnancy, axial system, vibrations, TVS, spine

Thesis title: Pathological consequences of hypokinesis in paraplegic patient and their identification by TVS method The thesis focus: The focus of the thesis was to identify and classify differences of mechanical properties of axial systems between paraplegic patient and people from healthy population. Secondary focus of the thesis was to identify and classify changes of mechanical properties of axial system in paraplegic patient depending on physiotherapeutic intervention. The research methods: Three people, one paraplegic person and two healthy people were measured with TVS (Transfer Vibration Through Spine) method. Paraplegic person was measured twice, before and after one hour long physiotherapeutic intervention (PI). Healthy people were measured once, without PI. TVS method is a diagnostic apparatus that enables qualitative and quantitative classification of properties of axial skeleton and its segments. It is based on fact that velocity of mechanical waves and density of mechanical energy transmitting through axial skeleton is affected by properties of this system. Thus we were able to analyze and identify mechanical properties of measured axial systems according to differences of input and output values of acceleration on particular spinous processes. The results: When we compared frequency...

Axial piston machines are widely used in the industry ranging from aerospace, agriculture, automotive, heavy machinery, etc. These applications require better pumps and motors to meet current market demands such as higher power density in hydraulic units, smarter pumps (diagnostics and prognostics), higher efficiencies, and compactness. The current state-of-the-art in pump design is mostly based on heuristic design approach with very limited use of numerical toolssince the invention of this positive displacement machine until the present time. The numerical tools being used do not capture the physical phenomena in the thin fluid film between the rotating group components. The work presented in this dissertation aims to demonstrate the feasibility of virtual prototyping utilizing a combination of in-house developed multi-domain models and to propose a novel computational based design methodology for axial piston machines. The methodology is an iterative process between the virtual components in 3D CAD models and the function evaluations for the design requirements utilizing the numerical models which provide an accurate prediction to the behavior of the mechanical components working together. To validate the proposed methodology a case study on a 24 cc/rev axial piston machine was carried out. The machine was built virtually, simulated,and optimized for desired performance. A physical prototype was built based on the case study and tested successfullyfor forty-five operating conditions.

A estabilidade primária é decorrente da adaptação mecânica imediata entre o osso e o implante após a sua inserção. O sucesso desta adaptação depende de fatores como a densidade e qualidade ósseas, tamanho, diâmetro, forma e rugosidade da superfície do implante. As cargas oclusais aplicadas sobre o implante podem afetar o osso circundante. Esse estudo teve como objetivo avaliar, comparativamente, a estabilidade inicial de implantes ósseo inseridos em cilindros de osso suíno padronizados, em diferentes posicionamentos ósseos, com e sem a aplicação de carga, por meio de análises de imagens tridimensionais (microtomografia computadorizada) e análises mecânicas (Frequência de ressonância, Torque de inserção e Ensaio de arrancamento). Os cilindros ósseos foram preparados a partir de osso suíno e separados em 2 grupos conforme a área doadora: Grupo A: cilindros removidos da cabeça do fêmur (alta densidade óssea) e Grupo B: cilindros removidos do côndilo mandibular (baixa densidade óssea). Previamente aos procedimentos experimentais, os cilindros ósseos foram certificados através de análises de imagens 2D (radiografia digital), para garantir a uniformidade intra-grupos e distinção entre os grupos dos espécimes. Após a certificação, foram feitas microtomografias computadorizadas dos cilindros ósseos para análise tridimensional de imagens prévia à instalação dos implantes, avaliando os seguintes parâmetros: porcentagem de volume ósseo (BV/TV), separação trabecular (TbSp), razão entre a medida da área superficial do osso e o seu volume ósseo (BS/BV) e porcentagem de porosidade total (POTOT). Depois disso, foram selecionados 60 implantes, que foram divididos em 4 grupos, cada um com 15 implantes: G1 (cilindros ósseos de alta densidade com implante situados ao nível ósseo), G2 (cilindros ósseos de alta densidade com implante 2 mm infraósseo), G3 (cilindros ósseos de baixa densidade com implante ao nível ósseo) e G4 (cilindros de baixa densidade com implante 2 mm infraósseo). A instalação dos implantes seguiu o protocolo recomendado pelo fabricante e durante o procedimento foi realizada a medida do torque de inserção. Após a instalação dos implantes, os cilindros ósseos foram submetidos à nova análise tridimensional (com avaliação dos mesmos parâmetros anteriores, nas áreas intra-roscas e adjacente à estas, acrescidos da medida da área de contato ossoimplante (BIC). Foi então realizada a avaliação do Coeficiente de Estabilidade (ISQ), utilizando a análise de frequência de ressonância (Osstell®). Após essa avaliação, 5 implantes de cada grupo foram submetidos ao ensaio de arrancamento. Os 10 implantes de cada grupo restantes foram conectados a pilares protéticos adequados, os quais receberam uma aplicação de forças axial (G1, G2, G3 e G4, 5 implantes de cada grupo) e lateral (G1, G2, G3 e G4, 5 implantes de cada grupo). Após aplicação das forças, os cilindros ósseos foram submetidos a nova análise tridimensional com avaliação dos mesmos parâmetros descritos, a nova análise de frequência de ressonância e ao ensaio de arrancamento. As variáveis foram testadas em relação à normalidade dos dados. Para todas as análises foi considerado um nível de significância de 5%. As análises estatísticas foram realizadas com base nos dados absolutos obtidos durante a análise tridimensional em cada situação de carga (antes do implante, pósimplante e pós-carga) e com a variação entre os valores das situações pós-implante e póscarga (variação carga - implante). A avaliação estatística do parâmetro de análise de frequência de ressonância não encontrou diferenças estatisticamente significantes para as comparações entre grupos G1 versus G3 e G2 versus G4 nas avaliações pós implante e pós carga. Em relação ao torque de inserção, houve diferenças estatisticamente significantes para as comparações entre grupos com implantes instalados no mesmo nível G1 versus G3 e G2 versus G4. Os maiores valores de torque de inserção obtidos foram registrados nos grupos de alta densidade. A análise estatística do ensaio de arrancamento mostrou diferenças estatisticamente significantes para as comparações: G1 versus G3 (inicial) e G1 versus G4 (inicial). Após a aplicação de carga oclusal, pode-se constatar diferenças estatisticamente significantes para as comparações: G1 versus G3 e G2 versus G4, após aplicação de carga lateral a análise mostrou diferença estatisticamente significante para a comparação G3 versus G4. Os resultados das análises tridimensionais mostraram diferenças estatisticamente significantes para os parâmetros TbSp e POTOT na avaliação da área óssea intra-rosca. A avaliação dos dados de variação após a aplicação de carga oclusal e lateral para o parâmetro TbSp, mostrou diferenças estatisticamente significantes para as comparações G2 versus G4. Em relação ao parâmetro POTOT, a aplicação de carga oclusal e lateral mostrou diferença estatisticamente significante para as análises: G1 versus G2 e G2 versus G4. Em relação ao parâmetro BSBV a análise dos valores absolutos, mostrou diferenças estatisticamente significantes para a área óssea intra-rosca dos grupos de baixa densidade. Já a análise dos valores de variação, a aplicação de carga oclusal mostrou diferenças estatisticamente significantes para os grupos G1 versus G3, G2 versus G4 e G3 versus G4, enquanto a aplicação de carga não axial resultou em diferenças estatisticamente significantes para os grupos G3 versus G4 e G2 versus G4. Já a análise estatística dos dados de variação do parâmetro BV/TV, mostrou diferença estatisticamente significante para todas as comparações na área óssea intra-rosca após aplicação de carga oclusal e lateral. A análise estatística do parâmetro BIC mostrou diferenças significantes para os grupos de baixa densidade (G3 e G4) nas comparações pós implante e pós carga. Em relação aos dados de variação, pode-se constatar diferença estatisticamente significante na aplicação de carga axial para G1 versus G2 e G2 versus G4, enquanto a aplicação de carga lateral mostrou diferença estatisticamente significante para as comparações G1 versus G3 e G2 versus G4. De acordo com os dados obtidos pode-se concluir que a densidade óssea tem relação com a estabilidade primária de implantes, que cargas não axias são prejudiciais para o tecido ósseo peri-implantar e que o posicionamento infraósseo pode promover melhor resposta do tecido ósseo, principalmente em regiões de baixa densidade óssea. / With the increase of oral rehabilitation with implants, immediate load can be used to reduce the treatment time. It is important to perform correct treatment planning for immediate implant loading, using 3D image analysis. The subcrestal implant positioning is one of the possible factors that may impact the success of immediate loading implants. Objective: The aim of this study is to evaluate the initial stability of osseointegrated implants placed infra bone or at the bone level in standardized porcine bone cylinders, through image (microcomputerized tomography) and mechanical analysis (resonance frequency, insertion torque and pull out test). Sixty bone cylinders were prepared from fresh porcine bone and separated in 2 groups: Group A 30 cylinders removed from femur head (high bone density) and Group B - 30 cylinders removed from the mandibular condyle (low bone density). Before the experimental procedure, the bone cylinders were certificated through 2D images analysis (digital radiography) to calculated bone density. After this, the bone cylinders were evaluated through micro computed three-dimensional analysis before the implant insertion. The parameters were analyzed in 2 levels (L1-bone volume internal to the threads and L2 - immediately adjacent to the end of threads). The microtomographical parameters analyzed were: Bone volume/Total volume (BV/TV), Trabecular thickness (TbSp), Bone surface/Volume ratio (BS/BV) and Total porosity percent (POTOT). Then, 60 implants (Alvim, 3.5 mm x 10 mm, Neodent®, Curitiba) were inserted in bone cylinders (1 implant in each cylinder), according to manufacturers protocol, and insertion torque was recorded for each implant. After that, the bone cylinders were submitted a new micro computed tomography analysis that evaluated the same levels and parameters, and Bone Implant Contact (BIC) was also recorded. After that, 5 implants were submitted to pull out test while the others implants received axial and non- axial load. After that, a new microcomputerized tomography analysis evaluated the same levels and parameters previously described, and resonance frequency analysis and pullout test were performed in the bone cylinders. 3D analysis showed that pre- and post-implants intra-groups had statistically significant differences for TbSp and POTOT parameters, and for BSBV and BIC parameters there were observed statistically significant differences for low bone densities groups. The values of differences between post and before loading showed statistically significant differences between G2 and G4 for TbSp, POTOT, BSBV, BV/TV and BIC parameters. The RFA analysis showed highest values for G2 and G4. Concerning insertion torque, the highest mean values were found in high bone densities groups. The pullout strength test showed that the non- axial loads in the low bone density maybe lead to implant displacement throughout the implant insertion axis. Bone density has a direct relationship with implant primary stability. Non- axial loads are harmful to peri- implantar bone tissue and subcrestal placement of implants presented the best mechanical and tomographical results.